Planooraph co



A. T. DAWSON AND G. T. BUCKHAM.

FIRING MECHANISM OF QRDNANCE.

APPLICATION FILED PR. 18. I918.

Patented Aug. 5, 1919.

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Inventor.

A. T. DAWSON AND G. T. BUCKHAM.

FIRING MECHANISM OF ORDNANCE. APPLICATION FILED APR. I8. 1918.

Patented Aug. 5, 1919.

2 SHEETS-SHEET 2.

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THE COLUMBIA FLANOGRAPH co., WASHINGTON, IL. c.

UNITED STATES PATENT oEEioE.

ARTHUR TREVOR DAWSON AND GEORGE THOMAS'BUCKl-IAM, OE wEsTMINsTER,

ENGLAND.

Application filed April 18,

To all whom it may concern Be it known that we, Sir ARTHUR TREVOR .DawsoN, knight, and Sir GEORGE THoMAs BUCKHAM, knight, both subjects of the King of Great Britain, residing at Vickers House, Broadway, l/Vestminster, in the county of London, England, have invented certain new and useful Improvements in or Relating to the Firing Mechanism of Ordnance, of which the following is a. specification.

This invention relates to ordnance firing mechanism Of the kind hving a rocking hammer or striker which is carried by a lock frame slidably mounted in a box slide and intended tobe operated by hand when the breech screw is in the locked position as distinct from the type of firing mechanism in which the lock frame is automatically operated during the opening and closing movements of the breech screw to which type our invention is not intended to apply.

According to the invention we provide a safety device which moves angularly with the breech screw and which is so constructed and arranged as to engage with part of the hammer to prevent it from being displaced either rearward in the cocking direction or forw arl in the firing-direction into contact with the primer, when the breech screw is in. the unlocked position; the said device may also be of such a character that, at such times, it will prevent the lock frame from being moved toward the open position. In this manner we prevent the firing of the gun, and also the extraction of a used primer and the insertion of a new one, when the breech screw is in its unlocked position.

In order that the said invention may be clearly understood and readily carried into effect we will describe the same more fully with reference to the accompanying drawings in which .Figure 1 is a rear elevation showing a constructional form of the aforesaid safety device with the parts in the position occupied when the breech screw is fully locked.

Fig. 2 is a horizontal section of Fig. 1.

Fig. 3 is a rear elevation showing the lock frame moved aside toward the open position.

Fig. 4 is a sectionalplan showing the hammer withdrawn rearward.

Fig. 5 is a view similar to Fig. 3 but Specification of Letters Patent.

FIRING MECHANISM OF OBDNAN'CE.

1918. Serial No. 229,472;

showing the parts in the position they occupiy when the breech screw is unlocked, an

Fig. 6 is a sectional plan of Fig. 5 with the right hand portion in section on the line 6. 6.

A is the breech screw, 1 the carrier, A? the axial vent bolt, A the lock frame andA the primer extractor carried by the box slide A. B is the hammer pivoted at Z) to the lock frame.

In the example shown the aforesaid safety device comprises a sleeve C rotatably mounted in the carrier A around the box slide A and the rear end of the axial vent bolt A? and adapted to be angularly displaced, during the locking and unlocking of the breech screw, by a projection 0' thereon engaging. in a recess a in an extension a of the breech screw. This sleeve has a plate C provided with a ledge c which, when the breech screw is being unlocked. comes against a toe-piece 6 0n the hammer B (see Figs. 5 and 6) this toe-piece being so formed in relation to the ledge that forward and rearward movements of the hammer are prevented and it is also impossible to move the lock frame to the open position as will be seen from Fig.6. At this time it is therefore not possible either to. insert v a ,new primer or to extract the used one. The hammer is prevented from being moved rearward when the breech screw is unlocked, so as to hold the hammer rigidly in the retracted position. If this were not done and the hammer were moved rearward and released with the breech screw unlocked, the whole force of the blow of the hammer on its forward movement would have to be taken between the T-piece b of the hammer and the ledge c of the plate 0'. When however the breech screw is locked, the ledge 0 lies in the position shown by Figs. 1 to a in which its Offers no impediment to the rearward and forward movements of the hammer (see Fig. 4) or to the lateral movement of the lock frame (see Fig. 3); a primer'can thus at this time be inserted or extracted.

The sleeve C is detachably retained in position in the carrier by a removable pin C mounted in the carrier and adapted to engage in a slot 0* formed in the sleeve.

The means for moving the lock frame by Patented Aug. 5,1919.

hand comprise a handle A pivoted to an extension of the lock frame. To open the lock the handle A is moved in a clockwise direction about its pivot, thereby causing a bolt a to be withdrawn from a pocket in the rear face of the carrier; a lateral pull on the handle then shifts the lock frame to the open position.

What we claim and desire to secure by Letters Patent of the United States is 1. In ordnance breech mechanism, the combination with a hand operated lock frame having no operative connection with the breech actuating mechanism, and a rocking firing hammer carried by the lock frame, of a safety device, means for causing this device to move angularly with the breech screw so as to engage with the hammer when the breech screw is in the un locked position, and means whereby such engagement prevents rearward movement of the hammer from occurring.

2. In ordnance breech mechanism, the combination with a hand operated lock frame having no operative connection with the breech actuating mechanism, and a rocking firing hammer carried by the lock frame, of a safety device, means for causing this device to move angularly with the breech screw so as to engage with the hammer when the breech screw is in the unlocked position, and means whereby such engagement prevents forward movement of the hammer from occurring.

3. In ordnance breech mechanism, the combination with a hand operated lock frame having no operative connection with the breech actuating mechanism, and a rocking firing hammer carried by the lock frame,'of a safety device, means for causing this device to moveangularly with the breech screw so as to engage with the hammer when the breech screw is in the unlocked position and means whereby such engagement prevents opening movement of the lock frame from occurring.

7 5. In ordnance breech mechanism, the combination with a hand operated lock frame having no operative connection with the breech actuating mechanism, and a rocking firing hammer carried by the lock frame, of a sleeve, means for causing this sleeve to move angularly with the breech screw, a plate carried by said sleeve and a ledge on said plate engaging with a projection on the hammer, when the breech screw is in the unlocked position, for preventing the hammer from moving both rear ward and forward and also for preventing the lock frame from moving to the open position.

In testimony whereof we aflix our signatures.

ARTHUR TREVOR DAWSON. GEORGE THOMAS BUCKHAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents Washington, D. G." 

